The present invention generally relates to an actuator for moving a recording head and a method for producing the same, and more particularly to an actuator for moving a recording head, such as a magnetic head, which writes information on a disc recording medium, such as a magnetic disc, and/or reads the information therefrom and a method for producing the same.
For example, in a magnetic disc apparatus having a magnetic disc, such as a hard disc, in which information is stored, a pivoting type actuator moves a magnetic head in a radial direction of the magnetic disc. The magnetic head is located adjacent to the surface of the magnetic disc so as to write the information on the magnetic disc and/or read the information therefrom. The structure of this type of actuator is shown in FIG. 1. In FIG. 1, an actuator 1 has an actuator body 2, a driving coil 3 and a permanent magnet 4. A front end portion 2a of the actuator body 2 is provided with an arm (not shown in FIG. 1) having the magnetic head and rear end portion 2b of the actuator body 2a is provided with the driving coil 3. The driving coil 3 is adhered to the rear end portion 2b of the actuator body 2. A concave portion 2c is formed on an medium portion of the actuator body 2. Bearings 5 are engaged with the concave portion 2c. The permanent magnet 4 is fixed on the surface of a base 6 so that the driving coil 3 adhered to the actuator body 2 and the permanent magnet 4 are opposite to each other. A shaft 7 is pressed and fitted in a depression formed on the base 6 so that the shaft 7 projects from the base 6. The shaft 7 is engaged with a cylindrical supporting member 8 and the cylindrical supporting member 8 is engaged with the bearings 5 provided in the concave portion 2c of the actuator body 2. That is, the cylindrical supporting member 8 is put between the shaft 7 and the bearings 5 so as to rotatably support the actuator body 2. Therefore, the actuator body 2 is pivoted on the shaft 7 so that the magnetic head integrated with the actuator body 2 is moved in the radial direction of the magnetic disc.
In the actuator described above, the driving coil 3 is adhered to the rear end portion 2b of the actuator body 2 by an adhesive such as an UV hardening adhesive which is hardened adhesive when the UV hardening is subjected to an ultraviolet (UV) ray. When the adhesive is chemically changed, a gas is generated from the adhesive. Therefore, the magnetic disc can be corroded by the gas generated from the adhesive.
Thus, the actuator described above is produced as follows.
The driving coil 3 is adhered to the actuator body 2 by the UV hardening adhesive, and then the ultraviolet ray is applied to the UV hardening adhesive between the driving coil 3 and the actuator body 3 so that the UV hardening adhesive is cured. After that, the driving coil 3 and the actuator 2 integrated with each other are heated so that the gas is forcefully generated from the UV hardening adhesive. That is, a gas removing process in which the gas is forcefully generated from the UV hardening adhesive is performed. After the gas removing process is completed, the actuator body 2 is engaged with the cylindrical supporting member 8.
However, if the actuator body 2 is heated after the bearings 5 are pressed and fitted in the concave portion 2c of the actuator body 2, a quality of a grease with which the bearings 5 is filled deteriorates. Thus, the gas removing process in which the actuator body 2 and the driving coil 3 are heated must be performed before the bearings 5 are mounted in the concave portion 2c of the actuator body 2. That is, first, the driving coil 3 is adhered to the actuator body 2, second the driving coil 3 and the actuator body 2 are heated in the gas removing process, and third, the bearings 5 are mounted in the concave portion 2c of the actuator body 2.
In the conventional method for producing the actuator 1, as has been described above, it is impossible to assemble the actuator body 2, the driving coil 3 and the bearings 5 in one production process. That is, it is impossible to efficiently assemble the actuator body 2, the driving coil 3 and the bearings 5, so that the cost for the production of the actuator 1 is increased.